Ambiguity Function of Phased–MIMO Radar With Colocated Antennas and Its Properties

In recent years, multiple-input-multiple-output (MIMO) radar has been receiving increasing attention from researchers due to its numerous benefits. In contrast to conventional radar systems, it offers increased spatial resolution and improved parameter estimation, target tracking, and recognition performance. Recently, a combination of phased-array radar and MIMO radar, which is called Phased-MIMO radar, has also been proposed and studied. The ambiguity function has been a traditional and effective tool to investigate the range and Doppler resolution of conventional radar systems and is now being extended for MIMO radar systems. In this letter, the ambiguity function of the Phased-MIMO radar with overlapping subarrays has been formulated, and some mathematical properties of the ambiguity function have been derived. These properties can help when comparing the performance of conventional and MIMO radar systems. This letter can be considered an extension of the work done by Chen and Vaidyanathan for MIMO radar systems.